Compressing machine with automatic oil return



A. O. GIRARD.

COMPRESSING MACHINE WITH AUTOMATIC OIL RETURN.

' APPLICATION FILED APR. 25. 1919.

1A]. 6,?05,. T. Patented May 23, 1922;,

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APPLICATION FILED APR. 25, IEIIQ.

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ALFRED O. GIRARD, OF DECATUR, ILLINOIS, ASSIGNOR TO GLACIER REFRIGERATIIN'G- MACHINE 00., A COMMON LAW TRUST, ALFRED O. GIRARD, TRUSTEE, OF CHICAGO,

ILLINOIS.

COMPRESSING MACHINE WITH AIPIOMIATIC OIL RETURN.-

Specification of Letters Patent.

Patented May 23, 1922.

Application filed April 25, 1919. Serial No. 292,572.

To all whom it may concern:

Be it known that I, ALFRED O. GIRARD, a citizen of the United States, residing at Decatur, in the county of Macon and State of Illinois, have invented a certain new and useful Improvement in Compressing Machines with Automatic Oil Returns, of which the following is a specification.

This invention relates to compressing machines generally and particularly to refrigerating or ice making machines as a whole; also to equalizing va ves for use in such machines and elsewhere and to a relief valve mechanism for use in machines of the class described and elsewhere where it is necessary to transfer materials, such as oil, between chambers carrying different and varying pressures.

The object of the invention is to provide a machine of the class described in which the oil used in and carried by the compressing mechanism into the material such as ammonia compressed will be, under proper conditions in the operation of the machine, transferred back to the low pressure side or chamber of the machine and returned to the pump. The object is, more particularly, to provide the specific transfer mechanism between the high pressure and low pressure chambers of the machine and to provide a specific valve mechanism for automatically, temporarily equalizing the pressures in said chambers, thus permitting the transfer mechanism to operate.

The invention consists in means of carrying out the foregoing obj ectswhich can be easily and cheaply made, which is satisfactory in operation, and is not readily liable to get out of order. More particularly the invention consists in many special features and details of construction hereafter more fully set forth in the specification and claims.

Referring to the drawings, in which similar numerals represent the same parts throughout the several views,

Figure 1 is a vertical sectional detail View of one form of compression refrigerating which they assume in the operation of the device.

' Figure 5 is a sectional detail view on the line 55, of Figure 2.

Figure 6 is a similar view on the line 6-6 of Figure 3.

Figure 7 is an enlarged view of the eX- pansion and equalizing valve shown in Fig ure 1.

Figure 8 is a sectional view at right angles to that of Figure 7 taken on the line 88 of that figure.

Figure 9 is a sectional plan view on the line 9-9 of Figure 7.

Figure 10 is a perspective view of the end of the equalizing valve or cone.

Figure 11 is a sectional view on the line l1ll of Figure 12 showing an alternative construction for the equalizing passage.

Figure 12 is an enlarged sectional side view showing the relation of the valve cone to its seat under the construction of Figure 11.

The conventional form of refrigerating machine of the drawings has a case 14 on a base 16. In the lower case is the crank chamber or case 18 while in an upper cham ber 20 is located the ordinary ammonia coil 22 surrounding the pump or compressor cylinder 24 whose vertically reciprocatable piston 26 is driven by connecting rod 28, propelled by crank pin 30, rotated in chamber 18 by shaft 32. Coil 22 serves the function of a water cooled condensing coil in water chamber 20 to convert ammonia gas into liquid ammonia.

In the operation of the device the crank case 18 contains a suitable quantity of oil for lubricating the crank shaft mechanism and pump, and a portion of this oil is necessarily and intentionally carried by the pumped material, ammonia, through the pump cylinder 24 and thence through the proceeds through pipe 46, screen 48, passage 50, to the customary conical expansion valve 52 which lets it expand in the usual way into the working coil 54 which does the refrigerat'ng. In the operation of the machine chamber 42 is flooded with liquid ammonia but it does not at that time pass through chamber 60 for the reason that chamber 42 is full of oil which being heavier than ammonia occupies the bottom of the chamber 42 and excludes the ammonia from the entrance to pipe 60. The upper end of pipe 44 is raised to near the top of chamber 42 merely to keep oil from flowing out of chamber 42 through pipe 44. It does not in any way prevent the flow of liquid ammonia. As the flow through chamber 42 is very slow the oil has a chance to settle in chamber 42 and pass into chamber 60 in the manner described while the ammonia goes out of passage 44. From this coil it returns through pipe 56 and passage 58, to the crank case 18. When the pump is Working the pressure of the ammonia from the time it leaves the piston 26 until it passes the valve 52 is very much higher than it is in passing from pipes 56 and 58 into the crank case, and the problem to be solved is to provide a valve mechanism between the chamber-42'and the pipe 58 which will automatically during a complete cycle of operation of the machine,v

transfer the oil in settling chamber 42 back to the crank case. The device of this invention used for this purpose utilizes the vari- 1 most position shown Figure 2)by a relatively strong compression sprmg 64, the outer one of the two shown in the figures last referred to. Passage 60 terminates at its lower end in a restricted passageway 61 closed at its upper end by valve 66, carried by a rod 68 driven to its seat by pressure on the upper end of the rod 68 at 80 and held by the difference in pressure in chamber 60 and in passage 61. v

The lower end of rod 68 below valve 66 is made of triangular form 70 shown in section in Figure 6 or other suitable form so as to provide passages 72 through which oil passing below valve 66, when in the position of Figure 2, can readily travel without destroying the guidance of rod 68 in passage 61.

On the upper end of rod 68 is an enlarged I triangular member 74 sliding in a circular passageway 76 through valve block 62 so as to leave 'o1l passages 78 through which oil can pass in all positions of member 74 in passage 78. This block 74 guides the upper end of rod 68 in passage 78 just as member 70 guides rod 68 in passage 61. On the upper end'of block 74, is a valve 80 seating itself at 82 in block 62.

Interposed between block 62 and valve member 66 and about rod 68 is a spring 83, the smaller of the two shown, which in the positions shown in Figures 2 and 3 holds the valve 80 on its seat 82.

The rod 68 is made of such a length that when, as shown in Figure 2, there is no pressure on the top of the block 62 spring 83 holds valve 80 on its seat 82 in block 62 and that when block 62 is held against its seat 85 valve 66 is off from its seat and open.-

When the parts are assembled and there is no material pressure above block 62 the valves assume the position shown in Figures 1 and 2 and no oil can ass from the chamber 42. When there is sufiicient pressure above chamber 60, in chamber 42 to move block 62 down through the position of Figure 3 to the position of Figure 4, thus opening valve 80, oil can pass from above past valve 80 and its seat 82 through passage 78 into chamber 60; thus filling it, but as valve 66 is closed neither oil nor ammonia can pass through into passage 61 and back to the crank case. When suflicient oil has passed from chamber 42 into passage60 so that the pressure in passage 60 is equal to that in 42 spring 83 moves the parts to the position of Figure 3 where they remain until the machine stops and the pressure in the whole machine equalizes.

When the pump stops and through the operation of valve 52, hereafter described in detail, the difference in pressure between chamber 42 and passage 61 reduces to substantial equality, spring 64 moves block 62 upward from the position of Figure 3 to the position of Figure 2, thus opening valve 66 and allowing the oil previously stored in passage 60 to move down through passages 61 and 58 to the crank case. 1

The parts remain in the position of Figure 2 until, on restarting, pressure is re-established and block 62 is again driven downward, thus first closing valve 66 and then opening valve 80 and permitting chamber 60 to again fill.

The opportunity for reducing the difference in pressure between chamber 42 and passage 58 when the ice machine stops, is given by the use of an exceedingly narrow channel 84 cut in one form of the device in the tip of conical valve 52 which is otherwise of ordinary construction. In the alternative form of the device a corresponding channel 85 is cut in the valve seat in which valve 52 fits. This channel 84, or 85 as the case may be, is small enough so that it does not effect the ordinary operation of the valve in the control of the ice machine in the ordinary manner, but itis large enough so that when the ice machine stops there is sufficient slow leak through the channel to ultimately reduce or equalize the pressure of the different parts of the machine as described, and thus cause the automatic operation of the oil transfer mechanism. Obviously unless an automatic slow leak is provided through the valve mechanism 52 there cannot be the necessary equalization in pressure on opposite sides of the oil transfer mechanism to operate it.

The particular form of valve 52 to which the channel 84 is applied, is the ordinary conical valve of ice machines. It is supported on aspring 86 which bears upon the underside of a flange 88 below the valve member 52. The upper side of this flange 88 supports rods 90 whose upper ends engage through the obvious mechanism shown in the drawings a diaphragm 92 closing the bottom of the usual thermostatic chamber 94 within which is placed a spring 96 adjustably controllable by the screw 98, all well understood in the art.

In the complete operation of the machine the refrigerating material, such as ammonia, is pumped through the crank case 18 into the coil 22 from which it passes to chamber 42 and thence to and past valve 52 to coils 54 and back to .the crank case. While the machine is working at its normal high pressure, the oil transfer mechanism stands at the position shown in Figure 4 until passage 60 fills, when the parts move to the position of Figure 3.

When the machine is stopped the pressures are sufficiently equalized by valve 52, as described, so that the valve transfer-mechanism moves to the position in Figure 2, thus permitting the contents of passage 60 to travel back to the crank case. On restarting the machine the operation is repeated. In practice, the machine is stopped and started often enough so that the mechanism transfers all the oil which' accumulates in chamber 42.

One great benefit of the device is that it prevents the oil going into the freezing or expansion coils, thus coating the pipes and reducing efliciency. Another benefit is that reoiling from the outside is necessary only at. long intervals. A very important point in home installations where the matter is apt to be neglected. In other words the machine is fool proof.

Another advantage is that a lower power motor canv be used to operate the machine because it starts with equal pressures i. e. at no load.

A further advantage is that when the machine stands idle the pressure of the ammonia is equalized through the entire machine, thus reducing the danger of leaks and breakage due to the expansion of the ammonia under external heat I Having thus described my invention what I claim as new and desire to secure by Letters Patent, is

1. In the machine of the class described having high and low pressure chambers, automatic means for equalizing the pressures of said chambers, there being an oil passage between said chambers, valve mechanism in the oil passage, operative when there is working pressure in the high pressure chamher to pass oil from the high pressure chamber into said oil passage and automatically movable when the pressures in the two chambers are more nearly equalized to a position to pass oil from the oil passage to the low pressure chamber, there being at no time an open path through said passage for the purposes set forth.

2. In a machine of the class described having a high and a low pressure chamber there being an oil passage between them, an independently located automatic relief valve between them, valve mechanism in the oil passage operative when there is working pressure in the high pressure chamber to pass oil from the high pressure chamber into said oil passage and movable, when the pressures in the two chambers are more nearly equalized, to a position to pass oil from the oil passage to the low pressure chamber, there being at no time a clear open path through said passage, and means in the relief valve automatically equalizing the pressures in the two chambers when the machine stops.

3. In the machine of the class described having high and low pressure chambers, automatic spring controlled means for equalizing the pressures of said chambers, there being an oil passage between said chambers, valve mechanism in the oil passage, operative when there is working pressure in. the high pressure chamber to pass oil from the high pressure chamber into said oil passage and automatically movable when the pressures in the two chambers are more nearly equalized to a position to pass oil from the oil passage to the low pressure chamber, there being at no time an open. path through said passage for the purposes set forth.

4. In a machine of the class described having a high and low pressure chamber there being an oil passage between them, an in dependently located automatic spring controlled relief valve between them, valve mechanism in the oil passage operative when there is working pressure in the high pressure chamber to pass oil from the high pressure chamber into said oil passage and m'ovable, when the pressures in the two chambers are more nearly equalized, to a position to pass oil from the oil passage to scribed my name in the presence of two the low pressure chamber, there being at no Witnesses.

time a clear open path through said passage,

and means in the relief valve automatically equalizing the pressures in the two chambers l/Vitnesses:

when the machine stops. DWIGHT B. CHEE ER, In Witness whereof, I have hereunto su'b- ANNA ROSENTHAL.

ALFRED O. GIRARD. 

